Set in 1872, Sally Lockhart is sixteen and determined to discover the secrets behind her father's sudden death, even if it means putting her own life in danger as others try to stop her. As Sally searches for the answers she needs, her quest takes her from the grimy streets of London to a Maharajah's Indian Palace, to the opium dens of China and into a deep mystery whose heart is a priceless jewel soaked in blood.